Officials say the men did thousands of dollars in damage at the park in Calverton.
Billy Perry of West Islip is well known in the BMX circles, and he is known for pulling these types of stunts. On his Facebook page, he says he's wanted to do this for years.
Riverhead Police say they are investigating YouTube video which shows the 21-year-old Perry and his crew riding their bikes through the water park.
Perry details every step of their escapade in the 15-minute long video including the ride to the park.
The video shows them scaling a barbed wire fence to break into Splish Splash early Thanksgiving morning. Check it out here:
"If we don't get arrested, hopefully we don't get arrested, we tried to do it last year on New Year's but it was raining out in the morning," said Perry in the video. "It's Thanksgiving. so we're hoping there will be no one there. It's super early in the morning."
It was around 6 a.m. when Perry and his friends scaled the fence surrounding the property. Then they took off. After a while they were spotted by a security guard.
Park manager Mike Bengtson says the security guard notified Riverhead Police.
"There was damage to the attractions. We don't know the extent of that damage yet but they will all need to be re-inspected," said Bengston. "We just had some slides that we re-coated this year which was very expensive for us."
We tried to speak with Perry several times at his home in West Islip but no one came to the door.
Perry makes it clear in the YouTube video that he has no regrets about his crew's stunt.
"That was the most savage session in a long time," he said. "It's one of those things people say they want to do but they never do it. But we did it."